Real-time location systems (RTLS) are technology solutions that automatically identify and track the location of objects or people in real time, in most cases within a building such as a warehouse, shipping yard, hospital, or campus. In a typical implementation, wireless RTLS tags are affixed to objects or worn by people, and fixed reference points receive wireless signals from these tags to determine their location. Tags and fixed reference points can be transmitters, receivers or both, and this flexibility allows for multiple possible combinations. These solutions enable organizations to more effectively keep track of where things are, which can help them improve processes they are currently struggling with, such as inventory management.
RTLS systems are designed to replace outdated, less efficient solutions such as spreadsheets and clipboards, by automating tasks that are now largely manual and prone to errors. The RTLS systems are also valuable to businesses because they generate intelligence: Useful data about product and asset movement within facilities, how quickly processes are being completed, and what organizations such as hospitals can do to speed up services. Data gathered by these systems can be stored, analyzed, audited, and assessed by internal parties or external authorities such as public safety organizations.
Applications of RTLS typically aim to improve operational processes and workflows; safety and security; inventory management, or a combination of all of these. RTLS solution implementation can help organizations address specific challenges they are facing related to a range of causes including resource inefficiencies and even employee endangerment.
In the healthcare sector, hospitals and clinics can use the technology to track and manage assets such as medical equipment, through real-time visibility into the location and status of the equipment. This can potentially reduce inventory costs, cut down on the time it takes nurses, technicians and other healthcare professionals to locate missing equipment, reduce theft of high-cost systems, and automate the maintenance of equipment. Healthcare facilities can also decrease the amount of time patients have to wait between procedures, through automated alerting and monitoring of patient activity or inactivity. They can also enhance the safety of patients by keeping track of their whereabouts within a facility. One of the unique attributes of RTLS that makes it applicable to so many applications and industries is its ability to track the location of so many different types of assets, whether it's equipment, tools, shipping containers, measurement devices or vehicles. Knowing the exact location and condition of assets can help companies improve workflow processes—regardless of the type of business they provide.
RTLS is also valuable because it can be used to track people. For industries such as healthcare, the benefits of this are clear: hospital administrators can follow a patient's journey through the emergency room, admission process, operating room, and hospital room—all the way through discharge. Tracking such metrics as wait times during these various stages in the patients' journey helps administrators to better address potential patient flow challenges. People-tracking using RTLS can also be used to improve safety. Through the use of security badges, people who work in harsh environmental conditions and remote processing plants can be tracked in case of emergencies. The technology can not only track the location of objects but their condition as well, through such capabilities as remote temperature and humidity monitoring. Industries that rely on products or materials being managed in optimal conditions, such as healthcare, food processing, pharmaceuticals, chemicals, etc., can benefit from ensuring that these products are stored and kept in the best possible conditions. The potential benefits include cost savings and, even more important, public safety.
RTLS configurations can vary significantly depending on what type of facilities the technology is being used in, the type of system, how it is being used, what types of products are being tracked, what conditions are being monitored, etc. A key piece of the RTLS configuration is the badge or “tag” that is used to provide location information. Tags are attached to whatever assets, equipment, or materials an organization wants to track, while badges are worn by people who can be tracked or who use the system to trigger alerts. These lightweight tags or badges transmit radio frequency signals periodically to access points, and subsequently to RTLS software. A single implementation can support as many as thousands of tags, but most deployments start much smaller and can be scaled up as needed. In “Active Tag” systems, the tags carry batteries which power the tag's operation for a period of months or years, until the battery dies or is replaced.
RTLS systems with active tags usually employ a process to monitor the battery status of the tag, and attempt to alert or warn system managers when a tag is reaching a low-battery status and needs to be serviced. Unfortunately, these processes are often unsuccessful in notifying the system's manager in time, or the system's manager is unable to replace the battery or tag before the battery fails. Once a battery fails on a tag or badge, and the asset or person moves to a new location, their location changes are invisible to the RTLS system. It becomes very difficult to find a dead-battery tag for several reasons: the tag can be carried anywhere within a large building like a hospital, and a dead tag looks exactly like a live tag, so a visual inspection is no help. Large-scale failures of 5% or 10% of tag batteries often cause a system's location reports to become unreliable, since a significant fraction of the tagged assets or people are not reporting to the system, and users lose faith in the ability of the system to track the tagged items and badged personnel. The value, efficiencies and safety features of the system are inhibited when large numbers of tag and badge batteries are dead.
Often, the RTLS system includes radio-communicating, battery-powered infrastructure devices as well, like beacons, sensors, or exciters, which provide a location reference or location-reference signal. These battery-powered devices are commonly monitored for battery life. While they are easier to service when they reach low-battery status because their locations are fixed, the system managers may find it difficult to monitor these dead-battery devices since they are no longer in radio communication with the network.
Some non-RTLS sensory systems are beginning to be introduced into the market which use energy harvesting to power the sensors. These devices lack a battery. Their advantage is that they do not have a battery that dies and renders the sensor useless. However, even with state-of-the art energy harvesting, the use of energy-harvesting technology alone is not practical for powering RTLS tags for their entire useful life. In practice, either the energy harvesting circuitry makes the tag so large as to be impractical for tagging small assets, or the energy-harvesting circuitry does not harvest enough energy to power a tag that can be located accurately at low latency.